Real Clear Politics average for all polls, Registered Voters and Likely Voters show Obama up by 3 points.

The RV polls have a systematic bias oversampling Democrats by a few points. This is well known, and polling companies will switch to LV polls. The reason they don't all use LV early results from differences in opinion as when LV becomes more reliable. The organizations that use RV now accept the fact it favors the Democrats by a few points, but they believe a systematic bias is better than what they consider as a more random bias with LV. One fact is clear, the enthusiasm gap among Republicans is double digits higher than among Democrats, so when all polls swing to LV, there will be more consistency.

The most extreme outlier poll that favors Obama by 10 points is using RV.